Patent documents 1 and 2 disclose door opening and closing mechanisms for opening and closing a front side part of a housing accommodating an electronic device, and thereby exposing and covering the electronic device.
Patent document 1 discloses a door opening and closing mechanism including a door that is rotated by a pair of rotating shafts to expose and cover an electronic device accommodated in a housing, wherein the rotating shafts are pivotally supported at places close to end portions of a lower side periphery of a front side opening of the housing.
Patent document 2 discloses a door opening and closing mechanism including a door that is rotated in a horizontal plane or in a vertical plane via a hinge to expose and cover an electronic device accommodated in a housing, wherein a peripheral part of a front side opening of the housing is provided with the hinge.